JPH097866A - Fly-back transformer - Google Patents

Abstract

PURPOSE: To obtain a fly-back transformer which is excellent in higher harmonic tuning and high-frequency operation, small in size, and high in output voltage by a method wherein a multiple voltage rectification circuit is connected between a winding terminating end of a split coil and a winding starting end of a following split coil. CONSTITUTION: The anode of a diode 4 out of a diode series circuit composed of three diodes 4, 5, and 6 connected in series so as to be of the same forward direction is connected to the winding terminating end Tb1 of a split coil L1. A capacitor C1 is connected between the cathode end T1 of the diode 4 and the winding starting end Ta1 of the split coil L1, and a capacitor c. is connected between the cathode end T1 and the winding starting end Ta2 of a split coil L2. A capacitor C3 is connected between the cathode end T2, of the diode 5 and the winding terminating end Tb1. A voltage doubler rectification circuit comprises the diodes 4, 5, and 6 and the capacitors C1, C2, and C3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flyback transformer used for driving a cathode ray tube.

[0002]

2. Description of the Related Art In recent years, as the screen of a cathode ray tube has become finer, a laminated type high voltage coil is widely used for a flyback transformer.

A multi-shingler will be described with reference to FIGS. 4 to 7.
A high-voltage coil of a laminated type will be described.

On the outer peripheral surfaces of both ends of the winding body 1 of the high-voltage coil bobbin, a plurality of columns Pa1 to Pan and Pb1 to Pbn are projected in parallel to each other in a direction perpendicular to the central axis L of the winding body 1. Set up. Each of these columns Pa1 to Pan, Pb1
Terminal pins 2 are further projected and planted at the tip end portions of Pbn to Pbn. Split coils L1 to Ln, which form a high-voltage coil, are wound around the winding drum 1 in a coaxial multi-layer manner. In addition,
In order to maintain insulation between the split coils L1 to Ln, an insulating film 3 is provided so as to sandwich the split coils L1 to Ln. Winding ends Tb1 to T of the split coils L1 to Ln-1
The node ends of the diodes D1 to Dn-1 are connected to bn-1, and the cathode ends of the diodes D1 to Dn-1 are connected to the divided coils L2 to L2 of the next layer. Ln
Is connected to the winding start ends Ta2 to Tan. The winding start end Ta1 of the split coil L1 is grounded. The winding end Tbn of the split coil Ln is connected to the anodic end of the diode Dn. After winding ends and winding ends of the split coils L1 to Ln connected to the terminal pin 2 and anodic ends and cathode ends of the diodes D1 to Dn are twisted to the terminal pin 2 and temporarily fixed, It is connected to the terminal pin 2 using a method such as welding or soldering.

In the laminated high-voltage coil, the smaller the number of turns of each split coil L1 to Ln, the more each split coil L.
The inductances and leakage inductances of 1 to Ln are reduced, and the line capacitances of the split coils L1 to Ln are reduced. As a result, the self-resonant frequency is increased, which is advantageous in high-order harmonic tuning and high-frequency operation.

[0006]

However, when the number of windings of each split coil constituting the laminated high-voltage coil is small, the voltage generated in each split coil becomes small, so that the output voltage of the high-voltage coil naturally becomes small. For this reason,
There is a problem in that the output voltage of the high voltage coil must be increased by increasing the number of layers of the split coil to make it multilayer. As a result, there is a drawback that the time required for winding the high voltage coil increases and the outer diameter of the high voltage coil increases due to the multilayer structure of the split coils, which in turn increases the size of the flyback transformer. Further, in the case of multiple layers, there is a drawback in that the higher-order harmonic tuning is lost due to an increase in interlayer capacitance between the divided coils forming the high-voltage coil, resulting in poor regulation of the output voltage of the high-voltage coil. It was Therefore, an object of the present invention is to provide a flyback transformer that is excellent in high-order harmonic tuning and high-frequency operation, and that is small in size and capable of obtaining a large output voltage.

[0007]

In order to achieve the above object, the present invention provides a flyback transformer having a high voltage coil composed of a plurality of laminated divided coils, in which the winding end of at least one divided coil and the division of the next layer. A multiple voltage rectifier circuit is connected between the winding start ends of the coil.

[0008]

A multi-voltage rectifier circuit is connected to the winding end of the split coil and the winding start end of the split coil which is the next layer, which constitutes the flyback transformer. The flyback pulse generated in this split coil is boosted to multiple voltage by the multiple voltage rectifier circuit and applied to the split coil of the next layer. For this reason,
A large voltage is output despite the small number of split coils.

[0009]

Embodiment An embodiment of the present invention will be described with reference to FIG. The same components as those in the conventional example are designated by the same reference numerals, and the description thereof will be omitted.

The winding start end Ta1 of the split coil L1 is grounded. At the winding end Tb1 of the split coil L1, three diodes 4, 5, and 6 are connected in series so that the forward direction is the same, and the anode of the diode 4 of the diode series circuit.
The terminal end side is connected. A capacitor C1 is provided between the cathode end T1 of the diode 4 and the winding start end Ta1 of the split coil L1.
And a capacitor C2 between the cathode end T1 of the diode 4 and the winding start end Ta2 of the split coil L2.
Is connected. A capacitor C3 is connected between the cathode end T2 of the diode 5 and the winding end Tb1 of the split coil L1. The diodes 4, 5 and 6 and the capacitors C1, C2 and C3 described above form a voltage doubler rectifier circuit.

At the winding end Tb2 of the split coil L2, three diodes 4, 5 and 6 are connected in series so that the forward direction is the same, and the anode of the diode 4 of the diode series circuit is connected. The terminal end side is connected. The cathode end T of the diode 4
1 is connected between the winding start end Ta2 of the split coil L2, and a capacitor C2 is connected between the cathode end T1 of the diode 4 and the cathode end of the diode 6. . A capacitor C3 is connected between the cathode end T2 of the diode 5 and the winding end Tb2 of the split coil L2. The diodes 4, 5 and 6 and the capacitors C1, C2 and C3 described above form a voltage doubler rectifier circuit. In addition,
The cathode end of the diode 6 is connected to the cathode ray tube. In this case, since the cathode ray tube capacitance C4 unique to the cathode ray tube is equivalently connected between the cathode end and the ground of the diode 6, the capacitor C2 is not connected to the voltage doubler rectifier circuit. The cathode ray tube capacitance C4 may be used instead of the capacitor C2.

Next, the circuit operation of the voltage doubler rectifier circuit will be described with reference to FIG.

First, when the flyback pulse Ep1 is generated in the split coil L1, the diode 4 and the capacitor C are generated by the positive pulse V1 of the flyback pulse Ep1.
A current 7 flows through the path of the first circuit consisting of 1 and the capacitor C1 is charged to the voltage V1. Due to the negative voltage V2 of the flyback pulse Ep1, the capacitor C1 and diode
The current 8 flows through the path of the second circuit formed by the capacitor 5 and the capacitor C3, and the capacitor C3 is charged to the voltage (V1 + V2). When a flyback pulse Ep2 is further generated in the split coil L1, a current 9 flows in the path of the third circuit composed of the capacitor C3, the diode 6, the capacitor C2 and the capacitor C1, and the capacitor C2 is charged to the voltage (2V1 + V2). To be done. At the same time, the current 7 also flows in the path of the first circuit, and the capacitor C1 receives the voltage V1.
Will be charged. As a result, the winding start end Ta of the split coil L2
2 has a high voltage (2V1) which is about twice the peak of the positive pulse V1.
+ V2) is supplied. In the flyback pulse, the voltage of V2 is much smaller than the voltage of V1,
Can be ignored. Similarly, due to the voltage doubler rectifying circuit connected to the split coil L2, a high voltage (2V1 + V2) approximately twice the peak of the positive pulse V1 is applied to the cathode end of the diode 6 which is the input end of the cathode ray tube. ) Is output. As a result, the split coils L1 and L2 and the circuit configuration of the two voltage-doubler rectifier circuits, that is, the split coils of two layers and the six diodes.
A high voltage (4V1 + 2V2) that is approximately four times as high as that of the positive pulse V1 is output by the combination of the switch and the six capacitors.
In order to obtain a higher voltage, a plurality of circuits in which a voltage doubler rectifier circuit is connected to the split coils are provided, and the cathode end of the diode 6 constituting the plurality of circuits and the split coils of other circuits. Connect the winding ends to each other. Further, the winding start ends of the split coils at one end of the mutually connected circuits are connected to the cathode end of the diode 6 of the voltage doubler rectifier circuit, and the cathode end of the diode 6 at the other end is connected to the cathode ray tube. Connect to. The cathode ray tube capacity C4 may be replaced with the capacitor C6 without connecting the condenser C2 of the voltage doubler rectifier circuit connected to the cathode ray tube. When the number of voltage doubler rectifier circuits is increased in this way, a higher voltage can be obtained by the operation of the voltage doubler rectifier circuits described above.

Next, referring to FIG. 3, the high voltage coil bobbin supports the columns Pa1 to Pa4 and Pb1 to Pb4 with the diode 4,
A method for connecting the capacitors 5, 6 and the capacitors C1, C2, C3 will be described.

The winding start end Ta1 of the split coil L1 wound around the winding body 1 of the high-voltage coil bobbin is connected to the terminal pin 2 of the support column Pa1, and the winding end Tb1 is connected to the terminal pin 2 of the support column Pb2. Winding start end Ta2 of split coil L2
Is connected to the terminal pin 2 of the pillar Pa2, and the winding end Tb2
Is connected to the terminal pin 2 of the pillar Pb3. To the terminal pin 2 of the column Pa2, the cathode end side of the diode 6 of the diode series circuit composed of three diodes 4, 5 and 6 connected in series so that the forward direction is the same. The diode 4 is connected, and the anode end side of the diode 4 is connected to the terminal pin 2 of the support Pb2. Further, capacitors C1 and C2 are provided between the cathode end T1 of the diode 4 of the diode series circuit connected in series between the columns Pa2 and Pb2 and the terminal pins 2 of the columns Pa1 and Pa2. Are connected. A capacitor C3 is connected between the anode end T2 of the diode 6 and the terminal pin 2 of the support Pb2. Also,
Similarly, a diode consisting of three diodes 4, 5 and 6 connected in series is provided between the column Pa4 and the column Pb3.
The series circuit and the capacitors C1, C2, C3 are connected. The pillar Pa1 is connected to the ground, and the output voltage is taken out through the terminal pin 2 of the pillar Pa4. After wiring the diode series circuit composed of the diodes 4, 5 and 6 and the capacitors C1, C2 and C3 which compose the voltage doubler rectifier circuit to the substrate or the holder of the molded product, the substrate or the holder is connected. Prop Pa1-Pa4, Pb1-Pb4
It may be connected to the terminal pin 2 of.

[0016]

As described above, the present invention has the following effects.

(1) Since the number of turns of the split coil and the number of layers of the split coil can be reduced, deterioration of capacitive coupling of the high-voltage coil can be suppressed, and high-order harmonic tuning and electrical performance in high-frequency operation are improved. To do.

(2) Since the number of layers of the split coils can be reduced, the outer diameter of the high voltage coil can be reduced, and the flyback transformer can be made smaller and lighter.

[Brief description of drawings]

FIG. 1 is a diagram showing a state in which a voltage doubler rectifier circuit is connected to each of two layers of split coils that constitute a flyback transformer according to the present invention.

FIG. 2 is a diagram for explaining the circuit operation of the voltage doubler rectifier circuit of the flyback transformer according to the present invention, and FIG. 2 (a) shows the flyback pulse generated in the split coil.
(B) shows the current flow due to the flyback pulse.

FIG. 3 is a diagram showing a state in which a voltage doubler rectifier circuit according to the present invention is connected to a terminal pin of a high voltage coil bobbin.

FIG. 4 is a perspective view of a high voltage coil bobbin.

FIG. 5 is a sectional view showing a state in which a split coil is wound around a high voltage coil bobbin.

FIG. 6 is a view showing a state in which a diode forming a multi-single-type laminated high-voltage coil is connected to a terminal pin of a high-voltage coil bobbin.

FIG. 7 is a circuit diagram of a multi-single-type laminated high-voltage coil.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 winding body part 2 terminal pin 3 insulating layer 4, 5, 6 diode Pa1-Pan, Pb1-Pbn support | pillar L1-Ln split coil D1-Dn diode Ta1-Tan winding start end Tb1-Tbn split coil End of winding C1, C2, C3 capacitor C4 cathode ray tube capacity

Claims (1)

[Claims] 1. A flyback transformer having a high-voltage coil composed of a plurality of laminated divided coils, wherein a multiple voltage rectifier circuit is connected between the winding end of at least one divided coil and the winding start end of the divided coil of the next layer. This is a flyback transformer.